Ordered Monday received Thursday free across the country to the east coast. I am really enjoying these 510 soft cartomizers. The fit is not 100%. They leave a slight space between the battery and cartomizer but it is not a big deal at all, it fits firm. They have a slightly smaller diameter than the auto 510 battery BUT, for me, it is actually a good thing. I wanted to try these because I felt that the normal caromizers for the 510 feel slightly uncomfortable between my teeth. Because these are thinner it is much more comfortable even if it was not soft. As a matter of fact I would not trying a hard caromizer of the same diameter. Being that they are soft they are that much more comfortable. Another plus, that I did not think of, is that the soft material around the metal insulates the heat. I dont know now hot they get but I guess that is the point. Vapor production and throat hit is comparable to any other cartomizer I have used. I think they are great. The only down falls on these are two things. - does not hold as much liquid. This is a given but for me the benefits out weigh the extra refilling. - Paper material sticks to lips Its that much like a real cigarette. I wish that it used the same material that is on some other cartomizers that do not stick. Again these are great I highly recommend them. I might add another review to let you know how long they each last.